Oil burning appliance



oct. 25, 1938. l L L. BREESE, JR A 2,134,297

OIL BURNING APPLIANCE Filed Dec. 24, 1954 2 sheets-sheet 1 Oct. 25, 1938. L. BREESE, JR 2,134,297

OIL BURNING APPLIANCE- Filed Dec. 24, 1934 2 Sheets-Sheet 2 F' .4. i w I Y l Ik Patented Oct. 25, 1938 UNITED STATE-s PATENT OFFICE j Claims.

This invention relates to oil burning appliances, and has particular reference to an' automatic valve mechanism for such appliances by*which the quantity of oil flowing to the appliance for combustion purposes will be automatically regulated to maintain desired rates of combustion and uniform temperatures.

It is an object of the present invention to provide a simple yet efficient oil burner which may be employed for use in connection with domestic water heaters; stove and circulating warm-air heaters, garage heaters, poultry brooders and the like. In most of these applications, it is necessary that the burner shall operate at uniform combustion rates to produce for sustained periods of time substantially constant predetermined temperatures. Heretofore in oil burning appliances of this character, it has been customary to provide float actuated and other relatively complicated mechanisms for controlling the ow of oil at required rates to the burner, or to use thermostatically actuated electrical switches for opening and closing loil flow controlling valves. n

render the operation of such oil burning systems f inefiicient and unreliable.

Itis, therefore, a primary object of the present invention to provide an improved oil flow regulating valve mechanism for oilburning appliances of the character referred to wherein the oil inlet casing of the appliance is4 provided'with an oil ow passage and a valve seat with which-is engaged a needle valve which normally obstructs oilfiowpast said seat toward the combustion region of the appliance, the said casing and valves being formed from metals having diilerent coeicients of' expansion'which are interrelated an'd so disposed with respect to the combustion region of the appliance as to be responsive to combustion temperatures so that relative movement between said valve and its seat will take place to open and close said seat or passage to regulate the inflow of oil to the burner in accordance with the fuel demands of the burner. For a further understanding of the invention, reference is to be had to the following description and the accompanying drawings, wherein: Fig. 1 is a vertical sectional view taken through an oil burner and the oil flow controlling valve mechanism employed in connection therewith;

Fig. 2 is a similar View; the plane of the section being indicated b`y the line II-II of Fig. l; 'Fig. 3 is a detail sectional view' on the plane indicated by the line III- III of Fig. 1;

Fig. 4 is a horizontal sectional view onthe'plane indicated bythe line IV-IV of Fig. 1;

The oil burning apparatus disclosed in the accompanying drawings comprises a cylindrical retort I having horizontal rows of perforations 2 formed in the walls thereof. The bottom of the retort is Aseated within a metallic4 cup 3 having a bottom wall 4 of dished or concave form, the lower end of the retort resting on a horizontally disposed annular flange 5 of said cup, while the walls of the' cup above the ilange 5 closely and frictionally engage withthe lower walls of the retort. Directly connected with the lower surfaces of the bottom wall 4 is a valve casing 6, preferably formed from cast aluminum or other metal of high heat conductivity. The casing is attached to the bottom wall 4 preferably by means of screws 1 and 8, the latter being provided with a central bore 9 which constitutes the admission passage through which oil is led into thebottom of the retort for combustion purposes.-

'I'he casing G'includes an elongated substantially axially disposed passage I0, having its outer end internally threaded for the reception of the reduced threaded extension II of a valve seating fitting I2. I'his tting connects with an oil supply pipe I3 through which liquid oil obtained steel, whereas'the casing 6 and itsvassociated# fitting I2 have a much higher coeicient of ex-` pansion. By the use of these materials and the construction and arrangement of the valve parts as disclosed, the heating of the valve casing and its fitting I2 above normal atmospheric temperatures causes the casingv to expand, but since the valve I1 is stationarily supportedvwithin'the passage I 0 and is not effected to any appreciable extent by the increased temperature, an unseating of the valve takes place which allows passage of oil through the valve casing'and into the bottom of the retort for combustion purposes.

The support of the valve I1 within the casing 6 is effected, in the form of my invention illustrated in Fig. 4, by providing the outer axial portion of the casing 6 with an internally threaded socketfor the reception of an externally threaded adjusting screw I8. This screw is provided with an axial outwardly projecting stem I9 equipped at its outer end with a hand wheel by means of which the screw may be rotated and advanced back and forth to various positions of adjustment in the casing socket. The stem I9 preferably receives a packing 2| to prevent fluid seepage. 'Ihe inner end of the screw I8 terminates in a reduced tubular extension 22 formed near the end thereof with openings 23 for the reception of a transversely extending pin 24, which passes through the outer end of the valve rod I1, and a coil spring.25 is arranged within the extension 22 and engages the end of the valve rod to normally force the pin 24 thereof into contact withthe end walls of the elongated openings 23. The

hand wheel 20 is provided with spaced lugs 26 which are arranged for engagement with a stationary stop arm 21 projecting from one end of the valve casing 6, whereby the extent of adjustment of the screw I8 may be limited to control the amount of relative longitudinal movement which may take place between the valve rod and the extension 22 of the screw I8, whereby to provide for adjustments in the position of the needle valve in order to provide for high, intermediate and low rates of combustion of fuel in the associated oil burning apparatus.

The upper end of the perforated retort I is provided with a fixed stationary cap 28 formed with an axially disposedl vertically arranged burner tube 29. The annular wall .of the cap 28 above the annular upper edge of the retort wall is perforated as at 30, and above the perforations 30, the cap terminates in an outwardly and horizontally directed annular flange 3 I. Seated upon this ange is a horizontal top wall 32 of a stationary burner casing 33, which is of greater diameter than the retort I in order to provide an annular air circulating space 34.- 'I'he bottom of the casing 33 isopen to the atmosphere, so that airo may enter the space 34, pass upwardly through the same, thence throughthe perforations 36 of the cap 28 and outwardly of the casing by wayof an opening 35 in which is positioned the somewhat smaller upper end of the tube 29, whereby air may unite withthe vaporized mixture leaving the retort .by way of the tube 29 to produce highly efiicient combustion of the fuel.

In further carrying out the emcient combustion of the liquid fuel introduced into the bottom of the retort, use is made of anl air distributing head vwhich comprises a tube 36 securedin connection with a socket 31 formed in the top wall 32 of the casing 33. The tube 36 extends upwardly from the socket 31 andi'terminates in a horizontally directed extension 38 provided with anges 39, as shown in Fig. 2. Seated on the flanges 39 is a perforated air distributing cone 48, which is held in place by the vertical Vscrew 4I, the said cone being provided with upper and lower horizontal rows of perforations 42. The distributing cone `43' acts to introduce a tertiary body of air into the vaporized combustible mixture issuing from the top of the retort by way of the tube 36in order to complete combustion of the mixture in an eillcient manner with but minimum formation of smoke and carbon.l

Additional control of the -air supply to th burner is obtained by the provision'of an air admitting elbow 43 which terminates within the retort in an axially disposed downwardly projecting open-ended nozzle 44, the open end of the latter being spaced-from the concave lower wall 4 of the retort. 'I'he elbow 43 'is secured as at 45 to the vertical wall of the retort and is connected with an air supply pipe 46, which may project through the wall of the outer casing 33. The pipe 46 is connected with fan means 46", as illustrated in Fig. 2 for delivering air under pressure to the burner. vided with a strap 41, which is equipped with a thumb screw 48 disposed for engagement with the under side of the valve casing 6, whereby to retain the various parts of the burner assembly in rigidly secured fixed relationship. Y

In the operation of my improved oil burning apparatus, it will be observed that there exists a principle of reciprocal action between the oil admitting valve and the heat or temperature of fuel combustion. It will be noted that the valve I1 opens and closes entirely by reason of temperature changes which are developed in operation within theburner itself. When active combustion takes place within the retort, near its bottom wall 4, the temperature of the lower portion of the retort is increased, andthis increased `temperature is transmitted to the heat conducting' material from which the valve casing is formed, causing the valve casing to expandfand move away from the tapered end of the valve rod to increase the flow of oil into the retort. This results in producing a greater body of oil within the bottom of the retort, which admixes th the air drawn from the atmosphere through the perfora- The bottom of the casing 33 is pro--l tions in the walls of the retort and through the air elbow 43 so that operating on the Bunsen principle, the region of combustion raises to its mouth of the burner, as represented by the upper end oi.' the tube=29, and the visible combustion llame drops down into the retort only when the burner is receiving an insufficient quantity of oil.

l This .action automatically brings about la replenishment of oil byvariation in the vertical position of thefire. In other words,'when the nre begins to be starved for lack of oil to suptopof the burner -down into the retort, where its proximity to the oil valve causes thevalve to open and release more oil. As more oil is released into the burner, the fire is driven upwardly to' its normal top position and the oil'fiow stops until again demanded byastarv "ilre. f y

. The oil vaporizing control .disclosed in connection with the retort is such as to obtain what is knownfas the hydroxylating process of burning oil. In this hydroxylating process, the oil is changed by the radiant heat of the burner from a liquid into la gas and mixed with'air before combustion takes place, in much the same way as the Bunsen burner mixes the gas and air before combustlon. In a burner of this type, where the unit Aport it, it drops from its normal position at the is operating at the highest emciency, there is no fire burning in the retort', which means that 'EE floor of the retort or burner is relatively cool. As soon as a shortage of oil in comparison with the amount of air that is being constantly de;

livered takes place, a rareed mixture in the re" tort occurs, which results in the lowering of the .'fireandtheburningofthelatterintheretort.

This presence of the fire increases the temperature on the iloor ofthe burner or the retort, so that heat is `transmitted in greater'quantities to the aluminum valve casting comprising the casing of the oil valve and more oil is admitted to the burner to restore normal operation.

The air elbow is provided to inject an' added amount of air to the retort immediately above the oil inlet. This produces a rareied mixture which causes the fire to vburn and in turn increases the temperature of the valve, producing an increased flow of oil. As soon as enough oil is admitted to the retort to cover its floor with a film or body of liquid oil, the valve is insulated by this body of oil, causing it to cool off and minimize or check oil iiow.

The valve mechanism disclosed permits of the use not only of kerosene or equivalent, low boiling hydrocarbon oils but also the use of the better grades of fuel oil. The construction of the valve is such that it is practically impossible to permit the oil to build up flow obstructing guantities of .parain wax or the like on the valve seat, since the needle valve in closing presses rmly against the seat to remove clogging deposits. In starting the applancef it is merely necessary to inject by means of an oil can orthe like, a small quantity of oil into the retort, which may be ignited by means o f a taper. As soon as.this pilot combustion has been effected, the further operation of the apparatus becomes automatic. The

de vi'ce operates to burn oil very economically so that the heater may be used as a substitute for apparatus burning more expensive types of fuels.

What is claimed is: 1. An oil burner comprising a retort provided with a closed bottom, perforated side walls and' an open top, said top opening being of reduced size relative to thediameter of said retort, a short tube secured inthe top opening, a casing open at.its lower end' surrounding said retort and vspaced therefrom, said'casing having a top wall formed with an axial opening of a size slightly -greaterA than said tube to provide a space beed with a c0ncave`bottom wall, perforated side` walls and a top wall having a reduced axial opening, a burner tube positioned in said opening, a casing open at its lower end surrounding said retort and spaced Vtherefrom to provide an annular `draft chamber, said casing having a top wall formed with an axial opening of a diameter slightly greater than said burner tube, the open-- ing in the top wall of said casing providing for the discharge of air from the top of said draft chamber and into admixture with fuel constituents discharged from said tube, an air tube communicating with the draft chamber, a downwardly directed distributing cone connected with and a top wall having a reduced axial opening,

a burner tube positioned in said opening, a casing open at its lower end surrounding said retort and spaced therefrom to provide an annular` draft chamber, said casing having a top wall formed with an axial opening for the discharge of air from the top of said chamber, said opening being of a diameter slightly greater than said burner tube and through which said tube projects, an air tube communicating with the draft chamber, a downwardly directed distributing coneconnected with said air tube, said cone being rounding said retort and spaced therefrom to pro-` vide an annular draft chamber, 'a valve casing of metal readily expansible when subjected to heat directly secured to the bottom of said retort in intimate heat exchanging relationship therewith, the interior of said valve casing communicasing being formed with an internal valve seat, -a valve rod rigidly supported' at one end by said valve casing and engaging the valve seat at the other end, and an oil supply conduit connected with said valve casing at the end opposite that to which the valve rod is secured.

5. lIn oil burning apparatus, an oil vaporizing and combustion vessel of the hydroxylating type having a substantially closed bottom and an open top, a valve casing lformed from a material possessing a relatively high thermal expansion factor carried by and in direct heat exchanging re-f cating with the interior of said retort, said valve `lationship with the bottom of said vessel, said casing being formed with an oil conveying passage establishing flow between a source of oil supply and the interior lower portion of the vessel,

lthere being a valve s'eat in said passage, and valve jmeans cooperative with s aid seat, said means being formed from a material possessing a relatively low thermal expansion factor as compared with that of said casing, whereby the flow of oil through said passage increases or decreases in direct proportion to the increase or decrease in the temperature of the bottom of said vessel.

6. Inv an oil burner of the hydroxylating type havinga closed bottom, perforated side walls and an open top, a fuel control valve comprising a hollow body disposed in heat exchanging relationship with the burner bottom, said body being formed of metal having a high coefficient of expansion, a seat provided within said body adjacent the inlet thereto, the interior of said body being in open communication with the interior of said burner, and an elongated needlevalve positioned within said body and connected at one end therewith, the opposite tapered end of said valve having a high' coefllcient of expansion, a seat provided within vsaid body adjacent the inlet thereto, the interior of said body being in" open having a closed bottom, perforated side wallsand an open top; a fuel control valve comprising a tubular body secured intermediate of its ends to the bottom of said burner, said body being formed i of a metal having a high coeillcient of expansion, aseat provided within said body adjacent the inlet end thereof, the interior of said body being in open communication with the interior of said burner, and a needle valve disposed within said body and secured at one end thereto, the opposite tapered end of said valve being in engagement with said seat, said valve being formed of a metal vhaving a low coeiiicient of expansion. A

9. In an oil burner of the hydroxylating type having a closed bottom, perforated side walls and an open top, a fuel control valve comprising a tubular body carried by the bottom of said burn' `er, said body being formed of a metal having a high coeilicient o! expansion,a seat provided within said body adjacent the inlet end thereof, the interior oi said body being inopen communication with the interior of said burner, and a needle valve disposed within and resiliently secured at one end thereto,"the opposite tapered end oi said valve being in engagement with said seat, lsaidvalve being; Yformed oi'- a metal having a lower coemcient of expansion than that of said body. r

10. In an oil burner of the hydroxylating; type having a closed bottom, perforated side walls and an open top, a fuel control valve comprising a hollow body disposed in direct heat exchanging relationship with the bottom of said burner. said body being formed of a metal having a high coefficient of expansion, a seat provided within said body, the interior of said body beingin open communication with the interior of said burner, and a valve rod disposed within said body and 'adiustablysecured at one end thereto, the opposite endl of said valve rod engaging said seat, said valve rod being constructed of a metal having a lower coemcient of expansion than that of said valve body.

JAMES I. BREESE, Jn. 

